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Amino‐terminal processing of MIP‐1β/CCL4 by CD26/dipeptidyl‐peptidase IV
Author(s) -
Guan Ennan,
Wang Jinhai,
Norcross Michael A.
Publication year - 2004
Publication title -
journal of cellular biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.028
H-Index - 165
eISSN - 1097-4644
pISSN - 0730-2312
DOI - 10.1002/jcb.20041
Subject(s) - dipeptidyl peptidase , dipeptidyl peptidase 4 , biochemistry , enzyme , macrophage inflammatory protein , receptor , peptide , chemokine , secretion , t cell , biology , microbiology and biotechnology , chemistry , immunology , endocrinology , immune system , type 2 diabetes , diabetes mellitus
CD26 is a membrane‐bound ectopeptidase with dipeptidyl peptidase IV (DPPIV) activity that has diverse functional properties in T cell physiology and in regulation of bioactive peptides. We have previously reported that activated human peripheral lymphocytes (PBL) secrete an amino‐terminal truncated form of macrophage inflammatory protein (MIP)‐1β/(3–69) with novel functional specificity for CCR1, 2, and 5. In this report, we show that the full length MIP‐1β is processed by CD26/DPPIV to the truncated form and that cleavage can be blocked by DPPIV inhibitory peptides derived from HIV Tat(1–9) or the thromboxane A2 receptor, TAX2‐R(1–9). Addition of Tat(1–9) or TAX2‐R(1–9) peptides to PBL cultures partially blocks endogenous MIP‐1β processing. The kinetics of conversion of MIP‐1β from intact to MIP‐1β(3–69) in activated PBLs correlates with cell surface expression of CD26. Our results suggest that NH 2 ‐terminal processing of MIP‐1β and possibly other chemokines may depend on the balance between CD26/DPPIV enzymatic activity and cellular and viral proteins that modulate enzyme function. © 2004 Wiley‐Liss, Inc.